The Basel Convention of 1989 is concerned with:

The correct answer is D, wetland conservation. The Ramsar Convention on Wetlands of International Importance was signed in 1971 in the Iranian city of Ramsar and came into force in 1975. It is the only global environmental treaty devoted to a single type of ecosystem, and parties designate wetlands of international importance for the Ramsar List and undertake to maintain their ecological character. The second of February is observed as World Wetlands Day.

Option A, climate change, is the subject of the United Nations Framework Convention on Climate Change of 1992 and the protocols under it. Option B, pesticide pollution, comes closest to the Rotterdam Convention of 1998 on prior informed consent and the Stockholm Convention of 2001 on persistent organic pollutants. Option C, ozone layer depletion, belongs to the Vienna Convention of 1985 and the Montreal Protocol of 1987.

The correct answer is A. The Polar Code is the International Code for Ships Operating in Polar Waters, adopted by the International Maritime Organization and in force since the beginning of 2017. It is mandatory under the conventions on safety of life at sea and on prevention of pollution from ships, and it covers ship design, equipment, crew training and operation in ice-covered waters, as well as discharges of oil, sewage and garbage in the Arctic and the Antarctic.

Option B is wrong because territorial claims in the Arctic are dealt with under the law of the sea and the continental shelf procedure, not by this code. Option C describes what the Antarctic Treaty system and its environmental protocol do for scientific activity. Option D is wrong because the Arctic Council is a forum for cooperation on environment and sustainable development and does not conclude trade or security agreements.

The correct answer is D, Agenda 21. The United Nations Conference on Environment and Development, popularly called the Earth Summit, met at Rio de Janeiro in 1992 and adopted Agenda 21, a detailed non-binding programme of action for sustainable development. The number refers to the twenty-first century, for which the programme was drawn up, and its chapters cover poverty, consumption patterns, health, human settlements, atmosphere, oceans, waste and the role of major groups.

Options A, B and C, Agenda 39, Agenda 19 and Agenda 22, name no document at all and are included only to test whether the candidate remembers the number. The way to keep it straight is to link the twenty-one to the century that was about to begin, and to remember that the same summit also produced the Rio Declaration, the Forest Principles and the two conventions on climate change and biological diversity.

The correct answer is A, substances that deplete the ozone layer. The Montreal Protocol was adopted in 1987 under the Vienna Convention of 1985 and entered into force in 1989. It fixed timetables for phasing out chlorofluorocarbons, halons, carbon tetrachloride and other ozone depleting chemicals, with later deadlines for developing countries. Universal participation and steady tightening of the schedules have made it the most effective of all environmental treaties.

Option B, hazardous waste moving across borders, is the subject of the Basel Convention of 1989. Option C, migratory species, belongs to the Convention on Migratory Species of 1979, also called the Bonn Convention. Option D, trade in endangered species, is regulated by CITES, agreed at Washington in 1973. Each of these is a separate treaty with its own secretariat and its own conference of parties.

The correct answer is B, CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora. It was agreed at Washington in 1973 and came into force in 1975. Species are placed in three appendices: Appendix I covers species threatened with extinction, in which commercial trade is generally prohibited; Appendix II covers species that may become threatened unless trade is controlled; Appendix III covers species protected by a particular country that seeks the help of others.

Option A, the Ramsar Convention of 1971, protects wetlands of international importance and not wildlife trade. Option C, the Basel Convention of 1989, governs the movement of hazardous wastes between countries. Option D, the Rotterdam Convention of 1998, requires prior informed consent before certain hazardous chemicals and pesticides can be exported, which again is a chemicals treaty rather than a wildlife one.